CA1138241A - Sealing arrangement for a shutter of a pressure grinder - Google Patents
Sealing arrangement for a shutter of a pressure grinderInfo
- Publication number
- CA1138241A CA1138241A CA000353843A CA353843A CA1138241A CA 1138241 A CA1138241 A CA 1138241A CA 000353843 A CA000353843 A CA 000353843A CA 353843 A CA353843 A CA 353843A CA 1138241 A CA1138241 A CA 1138241A
- Authority
- CA
- Canada
- Prior art keywords
- shutter
- sealing
- support surface
- feeding chamber
- sealing element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000007789 sealing Methods 0.000 title claims abstract description 90
- 238000000227 grinding Methods 0.000 claims abstract description 19
- 238000004140 cleaning Methods 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 2
- 239000007921 spray Substances 0.000 claims 1
- 239000002023 wood Substances 0.000 abstract description 9
- 229910052729 chemical element Inorganic materials 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 3
- 208000036366 Sensation of pressure Diseases 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000003670 easy-to-clean Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
- D21B1/00—Fibrous raw materials or their mechanical treatment
- D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
- D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
- D21B1/14—Disintegrating in mills
- D21B1/18—Disintegrating in mills in magazine-type machines
- D21B1/24—Disintegrating in mills in magazine-type machines of the pocket type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27L—REMOVING BARK OR VESTIGES OF BRANCHES; SPLITTING WOOD; MANUFACTURE OF VENEER, WOODEN STICKS, WOOD SHAVINGS, WOOD FIBRES OR WOOD POWDER
- B27L11/00—Manufacture of wood shavings, chips, powder, or the like; Tools therefor
- B27L11/08—Manufacture of wood shavings, chips, powder, or the like; Tools therefor of wood fibres, e.g. produced by tearing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/46—Sealings with packing ring expanded or pressed into place by fluid pressure, e.g. inflatable packings
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Physics & Mathematics (AREA)
- Architecture (AREA)
- Fluid Mechanics (AREA)
- Manufacturing & Machinery (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Paper (AREA)
- Disintegrating Or Milling (AREA)
- Auxiliary Devices For Machine Tools (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
Abstract
Abstract of the Disclosure A sealing arrangement for a shutter for a feeding chamber of a continuously operating pressure grinder. The feeding chamber is provided with an inlet opening for feeding wood batches at atmos-pheric pressure into said feeding chamber and with an outlet open-ing for feeding said wood batches into the grinding chamber at over-pressure. Each opening of said feeding chamber is provided with a shutter movable between an opened position and a closed position for preventing of escape of said overpressure through said feeding chamber.
The feeding chamber is provided with a fixed guide supporting the shutter during its movement between opened and closed positions.
Said guide comprises two parallel support surfaces between which the shutter is slidably mounted. The distance between said support sur-faces is greater than the thickness of the shutter adjacent said support surfaces so that the shutter is displaceable towards and away from said support surfaces in a direction perpendicular to said support surfaces. A sealing element is provided in one of said support surfaces in such a way that, when the shutter is displaced away from said one support surface towards the other support sur-face, the shutter is released from contact with said sealing ele-ment. In this way the shutter is due to the pressure difference between opposite sides of the shutter pressed against said one support surface and against said sealing element but is released from contact with said support surface and said sealing element when the pressures are equilized on opposite sides of the shutter and can be moved to open and closed positions without said contact.
The feeding chamber is provided with a fixed guide supporting the shutter during its movement between opened and closed positions.
Said guide comprises two parallel support surfaces between which the shutter is slidably mounted. The distance between said support sur-faces is greater than the thickness of the shutter adjacent said support surfaces so that the shutter is displaceable towards and away from said support surfaces in a direction perpendicular to said support surfaces. A sealing element is provided in one of said support surfaces in such a way that, when the shutter is displaced away from said one support surface towards the other support sur-face, the shutter is released from contact with said sealing ele-ment. In this way the shutter is due to the pressure difference between opposite sides of the shutter pressed against said one support surface and against said sealing element but is released from contact with said support surface and said sealing element when the pressures are equilized on opposite sides of the shutter and can be moved to open and closed positions without said contact.
Description
The present invention relates to a sealing arrangement for a shutter for a feeding chamber of a continuously operating pres-sure grinder, said feeding chamber being provided with a fixed guide for the shutter rnovable between an open and a closed position and wi~h a sealing support surface for providing a sealing between the feeding chamber and the shutter in its closed position.
Finnish Patent No. ~7, 979 describes a method which makes possible the use of a pressure grinder for continuous grinding of wood blocks. According to this method, wood blocks are fed into the grinding chamber of the grinder through a feeding chamber limited by two shutters which are opened and closed in separate steps. In the feeding chamber positioned between the two shutters, the pressure is increased to correspond to the pressure in the grinding chamber before opening the shutter closing the opening from the feeding chamber to the grinding chamber and re-duced, respectively, to correspond to atmospheric pressure before opening the shutter closing the opening from the feeding chamber to the atmosphere.
However, when carrying out the known method described above, a thight and reliable sealing of said displaceable shutters presents a problem.
The sealing of the shutters is hampered by several factors.
One is the big size of the shutters,which is due to the size of the block batch required. The shutters must therefore by sturdy so as to resist the impacts caused by the blocks and the overpressure of the grinding chamber. However, the large size of the shutters makes it difficult to provide exact tolerances.
- Secondly, the feeding of the wood blocks into the grinding chamber requires rapid movements of the shutter so that the blocks will fall in good order into the grinding chamber and not prevent the closing of the shutter. Such rapid movements produce great frictional forces in the guide surfaces of the shutter, and espe-cially the static friction in the lnitial stage of the movement is considerable.
, 113~2~9L
Thirdly, in particular the shutter Ofthe feeding chamber fac-ing the grinding chamber has to operate under fouled and wearing conditions. Thust the sealing surface of the shutter cannot remain sufficien;ly clean and smocth to provide a reliable sealing.
For the above-mentioned reasons, conventional sealing cons~
tructions are not suitable for sealing the shu~ter of ~he feeding chamber in a continuously operating pressure grinder.
The object of the present invention is to provide a sealing arrangement which eleminates the above-mentioned disadvantages and makes possible to provide by simple means a reliable sealing of the shutter for a feeding chamber of a continuously operating pres-sure grinder. This object is achieved by means of a sealing arrange-ment according to the invention which is characterized in that the shutter is mounted with play on said guide so that the sh`utter is displaceable toward and away frorn said fixed support surface in a direction transverse to the path of movement of the shutter along said guide, and in that a sealing element facing the shutter is mounted onsaid fixed support surface so that, as the shutter is displaced in a direction away from said ftxed support surface, the shutter is released from contact with said sealing elernent.
The invention is based on the idea ~hat the shutter can be lifted up from said guide into engagement with the fixed support surface and the sealing element provided therein when a pressure difference pressing prevails between opposite sides of the shutter which pressure difference causes the shutter ~to be pressed against the fixed support surface and, respectively, be lowered on said guide out of engagement with said support surface and said sealing element when equally high pressures prevail on opposite sides of the shutter. Thus, in the latter case, there will be a gap between the shutter a~d the support surface so that the shutter does not scrape against the support surface and the sealing element when the shutter is moved into the open position. The sealing between the shutter and the support surface is effected by means of the sealing element which engages the shutter seaiingly only when said pressure difference prevails between opposite sides of the shutter. Wen equally high pressures are acting on both sides of the shutter, the shutter has beeh lowered out of engagement with the
Finnish Patent No. ~7, 979 describes a method which makes possible the use of a pressure grinder for continuous grinding of wood blocks. According to this method, wood blocks are fed into the grinding chamber of the grinder through a feeding chamber limited by two shutters which are opened and closed in separate steps. In the feeding chamber positioned between the two shutters, the pressure is increased to correspond to the pressure in the grinding chamber before opening the shutter closing the opening from the feeding chamber to the grinding chamber and re-duced, respectively, to correspond to atmospheric pressure before opening the shutter closing the opening from the feeding chamber to the atmosphere.
However, when carrying out the known method described above, a thight and reliable sealing of said displaceable shutters presents a problem.
The sealing of the shutters is hampered by several factors.
One is the big size of the shutters,which is due to the size of the block batch required. The shutters must therefore by sturdy so as to resist the impacts caused by the blocks and the overpressure of the grinding chamber. However, the large size of the shutters makes it difficult to provide exact tolerances.
- Secondly, the feeding of the wood blocks into the grinding chamber requires rapid movements of the shutter so that the blocks will fall in good order into the grinding chamber and not prevent the closing of the shutter. Such rapid movements produce great frictional forces in the guide surfaces of the shutter, and espe-cially the static friction in the lnitial stage of the movement is considerable.
, 113~2~9L
Thirdly, in particular the shutter Ofthe feeding chamber fac-ing the grinding chamber has to operate under fouled and wearing conditions. Thust the sealing surface of the shutter cannot remain sufficien;ly clean and smocth to provide a reliable sealing.
For the above-mentioned reasons, conventional sealing cons~
tructions are not suitable for sealing the shu~ter of ~he feeding chamber in a continuously operating pressure grinder.
The object of the present invention is to provide a sealing arrangement which eleminates the above-mentioned disadvantages and makes possible to provide by simple means a reliable sealing of the shutter for a feeding chamber of a continuously operating pres-sure grinder. This object is achieved by means of a sealing arrange-ment according to the invention which is characterized in that the shutter is mounted with play on said guide so that the sh`utter is displaceable toward and away frorn said fixed support surface in a direction transverse to the path of movement of the shutter along said guide, and in that a sealing element facing the shutter is mounted onsaid fixed support surface so that, as the shutter is displaced in a direction away from said ftxed support surface, the shutter is released from contact with said sealing elernent.
The invention is based on the idea ~hat the shutter can be lifted up from said guide into engagement with the fixed support surface and the sealing element provided therein when a pressure difference pressing prevails between opposite sides of the shutter which pressure difference causes the shutter ~to be pressed against the fixed support surface and, respectively, be lowered on said guide out of engagement with said support surface and said sealing element when equally high pressures prevail on opposite sides of the shutter. Thus, in the latter case, there will be a gap between the shutter a~d the support surface so that the shutter does not scrape against the support surface and the sealing element when the shutter is moved into the open position. The sealing between the shutter and the support surface is effected by means of the sealing element which engages the shutter seaiingly only when said pressure difference prevails between opposite sides of the shutter. Wen equally high pressures are acting on both sides of the shutter, the shutter has beeh lowered out of engagement with the
- 2 -1136~
sealing element and the shutter can be opened without scraping against the sealing element.
Preferably, the sealing element is e~pandable by means of a pressure medium. In this case, the distance over which the shut-ter must be displaced away from the support surface and the seal-ing element before opening the shutter can be shortened because the sealing element can be of such a type which, when cortracted, will be withdrawn into the support surface and will only under pressure expand outside the support surface.
Because it is possible that the expansible sealing element may be damaged, e.g., due to mechanical damage9 the support sur-face is preferably provided with a second`safety sealing element.
This spare sealing element can be identical with the expansible sealing element acting as a main sealing or, for example, a normal O-ri~ng against which the shutter is pressed when a pressure diffe-rence prevails between opposite sides of the~shutter.
In order to keep clean the shutter surfaces participating in the sealing, a cleaning means is preferably provided which by wiping, spraying and/or in any other manner cleans said surfaces of the shutter as the shutter is moved past said cleaning means.
The invention will now be described in more detail with reference to the accompayning drawings in which Figure 1 is a vertical section of a pressure grinder provid-ed with a sealing arrangement according to the invention, and Figures 2 and 3 are cross-sectional vi'ews on an enlarged scale of the sealing point in a vertical plane parallel to the direction of movement of the shutter and in a vertical plane per-pendicular thereto, respectively.
The pressure grinder shown in the drawings comprises a frame 1, a grinding chamber 2 in said frame, a grinding stone 3 rotatably mounted in said grinding chamber, a feeding chamber 4 supported by said frame, an inlet opening 5 and an outlet opening 6 located in the upper and lower part, respectively, of said feeding chamber, shutters 7 displaceably mounted in the upper and lower part of said feeding chamber, and a pushing element ~ displaceably mounted under said feeding chamber.
According to the principle of operation of the pressure grinder wood blocks 9 to be ground are dropped into the feeding chamber 4 while the upper shutter is o?en and the lower ~13~:24~
shutter is ciosed whereupon the upper shutter is closed.
By opening a valve 11 in a conduit 10 connecting the f.eding char!lbcl- with the grinding chamber, a pressure corres-podnirlg to lhe overpressure (e.g., 1 to 3 bal-) acting in the grind-ing chamber is obtained in ~he feeding chamber. Hereafter, the lower shutter is opened whereby the blocks in the feeding chamber will fall down into the ~rinding charnber. By closing the valve and by opening a valve 13 in a conduit 12 connecting the feeding chamber to the atmosphere, atmospheric pressure is obtained irl the feeding chamber whereby the upper shut~er can again be opened for a new batch of wood.
Each shutter is guided by a guide 14 prov ded with parallel supprt surfaces 15,16 (Figures 2 and 3~ positioned at a distance above each other. The shutter is mounted in the slit 17 formed be-tween said surfaces. According to the invention, the shutter is mounted with play in the guide, i.e. the thickness of the edge portion 7a of the shutter is smaller than the distance between the support surfaces 15, 16 of the guide.
The upper support surface 15 of each guide which extends around all four sides of the feeding chamber is provided with a groove 18 in which is mounted a tubular, expandable sealing tube 19 which, as a continuous ring, encircles the opening 5 and 6 res pectively of the feeding chamber. The inner space of the sealing tube is by means of a conduit 20 connected with a three-way valve 21 provided with connections 22, 23 to a sou'rce of pressure air or pressure liquid (not shown) and to the atmosphere, respectively.
The upper support surface 15 of the guide serves as a holder for the expandable sealing tube 19.
The upper supprt surface 15 of each guide is also provided with a groove 24 for an 0-ring 25 which outside said sealing tube 19 encircles the opening of th~ feeding chamber.
Behind that put of the support surface 15 which, in rela-t;on to the grinding stone 3, is located at the rear edge of the outlet opening 6 of the feeding chamber are fastened a spring-loaded steel brush 26 contacting the upper surface of the shutter and a shower device 27.
The above-mentioned three-way valve 21 is provided with an adJjusting device 28 which, by means of a conduit 29, is connected with a sensor element'30, which, by means of conduits 31,senses the 11382~1 pressure di~ference between the feeding chamber 4 and the grinding chamber 2.
When the upper shutter 7 has been closed after the batch of wood 9 has been dropped into the feeding chamber 4 and the pressure in the feeding chamber has by opening the valve 11 been raised to the level of the pressure in the grinding chamber 2 and, according-1YJ no pressure difference prevails between opposite sides of the lower shutter 7J the sensing element 30 gives an impulse to the three-way valve 21 to reduce the overpressure of the expansible sealing tube 19 so as to draw the sealing away from the upper sur-face of the shutter and, in addition, also partly into its groove 18 in the support surface 15. As no pressure difference any longer pre-vails over the shutter, the shutter has dropped down on the lower support surface 16 of-the guide 14 and, accordingly, also out of contact with the spare sealing element 25. The shutter can now be pulled open without the shutter touching the upper support surface and the sealings. This has been illustrated by dotted lines in Figures 2 and 3.
After the batch of wood has dropped from the feeding chamber lnto the grtnding chamber, the lower shutter is again closed whereby the brush 26 and the water and air jets directed from the shower device 27 wtpe the surface of the shutter clean of any sticks and pulp. When the shutter has reached its closed position, the re-quired overpressure is by means of the three-way valve 21 created in the expandable sealing tube 19 whereby th~e sealing tube expands and seals against the shutter. Hereupon the connecting valve 11 is closed and the connection of the valve 13 from the feeding chamber to the atmosphere is opened. In this way, the feeding chamber will have atmospheric pressure whereby the overpressure in the grinding chamber causes the shutter to lift against the upper support sur-face 15 of the guide already at a pressure difference of about 0.5 bar. Thereby the sealing action of the expansible sealing tube 19 is further improved and the shutter is pressed also against the spare sealing element 25. Even if the overpressure would dis-appear from the expansible sealing tube 19, the spare sealing ele-ment 25 will prevent any leaks.
When the overpressure in the feeding chamber 4 has been balanced to correspond to atmospheric pressure, the upper shutter 7 113~41 can again be opened. As far as Lhe expansible sealing tube 19 and the spare sealing element 25 of the upper shutter are concerned, the operation is the sarne as described in connection with lower shutter. Thus, before being opened, the shutter has been lowered on the lower support surface 16 of the guide 14 out of contact with the upper support surface as well as the sealing tube and the sealing element.
Thanks to the invention, the shutters can be opened and closed without beingin contact with their sealing means and the support surfaces in which said sealing means are mounted. In spite of this, a reliable sealing will be obtained due to a pressure difference across the shutter. The sealing means are located, well protected against damage and fouling, under the upper support sur-~ face of each guide, and the upper surface of each shutter can be made smooth and easy to clean. Due to the expansion of the sealing tube, the gap between the support surface and the shutter can amount to, e.g., ~5 to 5 mm, preferably 2 to 3 mm.
The drawings and the specifications related thereto are onlyintended to illustrate the idea of the invention. In its details, the arrangement according to the inventton may vary within the scope of the claims. Instead of using an expansible sealing tube, a non-expansible sealing element can be provided which is mounted on an expandalbe ring or some other expandable seat. The invention can also be carried out by means of a non-expansible sealing ele-ment which is mounted substantially immovably,on a support surface, the distance between the support surface 15, 16 being selected somewhat bigger so that the shutter also in this case is disengaged from the sealing element before movement of the shutter.
;
.
sealing element and the shutter can be opened without scraping against the sealing element.
Preferably, the sealing element is e~pandable by means of a pressure medium. In this case, the distance over which the shut-ter must be displaced away from the support surface and the seal-ing element before opening the shutter can be shortened because the sealing element can be of such a type which, when cortracted, will be withdrawn into the support surface and will only under pressure expand outside the support surface.
Because it is possible that the expansible sealing element may be damaged, e.g., due to mechanical damage9 the support sur-face is preferably provided with a second`safety sealing element.
This spare sealing element can be identical with the expansible sealing element acting as a main sealing or, for example, a normal O-ri~ng against which the shutter is pressed when a pressure diffe-rence prevails between opposite sides of the~shutter.
In order to keep clean the shutter surfaces participating in the sealing, a cleaning means is preferably provided which by wiping, spraying and/or in any other manner cleans said surfaces of the shutter as the shutter is moved past said cleaning means.
The invention will now be described in more detail with reference to the accompayning drawings in which Figure 1 is a vertical section of a pressure grinder provid-ed with a sealing arrangement according to the invention, and Figures 2 and 3 are cross-sectional vi'ews on an enlarged scale of the sealing point in a vertical plane parallel to the direction of movement of the shutter and in a vertical plane per-pendicular thereto, respectively.
The pressure grinder shown in the drawings comprises a frame 1, a grinding chamber 2 in said frame, a grinding stone 3 rotatably mounted in said grinding chamber, a feeding chamber 4 supported by said frame, an inlet opening 5 and an outlet opening 6 located in the upper and lower part, respectively, of said feeding chamber, shutters 7 displaceably mounted in the upper and lower part of said feeding chamber, and a pushing element ~ displaceably mounted under said feeding chamber.
According to the principle of operation of the pressure grinder wood blocks 9 to be ground are dropped into the feeding chamber 4 while the upper shutter is o?en and the lower ~13~:24~
shutter is ciosed whereupon the upper shutter is closed.
By opening a valve 11 in a conduit 10 connecting the f.eding char!lbcl- with the grinding chamber, a pressure corres-podnirlg to lhe overpressure (e.g., 1 to 3 bal-) acting in the grind-ing chamber is obtained in ~he feeding chamber. Hereafter, the lower shutter is opened whereby the blocks in the feeding chamber will fall down into the ~rinding charnber. By closing the valve and by opening a valve 13 in a conduit 12 connecting the feeding chamber to the atmosphere, atmospheric pressure is obtained irl the feeding chamber whereby the upper shut~er can again be opened for a new batch of wood.
Each shutter is guided by a guide 14 prov ded with parallel supprt surfaces 15,16 (Figures 2 and 3~ positioned at a distance above each other. The shutter is mounted in the slit 17 formed be-tween said surfaces. According to the invention, the shutter is mounted with play in the guide, i.e. the thickness of the edge portion 7a of the shutter is smaller than the distance between the support surfaces 15, 16 of the guide.
The upper support surface 15 of each guide which extends around all four sides of the feeding chamber is provided with a groove 18 in which is mounted a tubular, expandable sealing tube 19 which, as a continuous ring, encircles the opening 5 and 6 res pectively of the feeding chamber. The inner space of the sealing tube is by means of a conduit 20 connected with a three-way valve 21 provided with connections 22, 23 to a sou'rce of pressure air or pressure liquid (not shown) and to the atmosphere, respectively.
The upper support surface 15 of the guide serves as a holder for the expandable sealing tube 19.
The upper supprt surface 15 of each guide is also provided with a groove 24 for an 0-ring 25 which outside said sealing tube 19 encircles the opening of th~ feeding chamber.
Behind that put of the support surface 15 which, in rela-t;on to the grinding stone 3, is located at the rear edge of the outlet opening 6 of the feeding chamber are fastened a spring-loaded steel brush 26 contacting the upper surface of the shutter and a shower device 27.
The above-mentioned three-way valve 21 is provided with an adJjusting device 28 which, by means of a conduit 29, is connected with a sensor element'30, which, by means of conduits 31,senses the 11382~1 pressure di~ference between the feeding chamber 4 and the grinding chamber 2.
When the upper shutter 7 has been closed after the batch of wood 9 has been dropped into the feeding chamber 4 and the pressure in the feeding chamber has by opening the valve 11 been raised to the level of the pressure in the grinding chamber 2 and, according-1YJ no pressure difference prevails between opposite sides of the lower shutter 7J the sensing element 30 gives an impulse to the three-way valve 21 to reduce the overpressure of the expansible sealing tube 19 so as to draw the sealing away from the upper sur-face of the shutter and, in addition, also partly into its groove 18 in the support surface 15. As no pressure difference any longer pre-vails over the shutter, the shutter has dropped down on the lower support surface 16 of-the guide 14 and, accordingly, also out of contact with the spare sealing element 25. The shutter can now be pulled open without the shutter touching the upper support surface and the sealings. This has been illustrated by dotted lines in Figures 2 and 3.
After the batch of wood has dropped from the feeding chamber lnto the grtnding chamber, the lower shutter is again closed whereby the brush 26 and the water and air jets directed from the shower device 27 wtpe the surface of the shutter clean of any sticks and pulp. When the shutter has reached its closed position, the re-quired overpressure is by means of the three-way valve 21 created in the expandable sealing tube 19 whereby th~e sealing tube expands and seals against the shutter. Hereupon the connecting valve 11 is closed and the connection of the valve 13 from the feeding chamber to the atmosphere is opened. In this way, the feeding chamber will have atmospheric pressure whereby the overpressure in the grinding chamber causes the shutter to lift against the upper support sur-face 15 of the guide already at a pressure difference of about 0.5 bar. Thereby the sealing action of the expansible sealing tube 19 is further improved and the shutter is pressed also against the spare sealing element 25. Even if the overpressure would dis-appear from the expansible sealing tube 19, the spare sealing ele-ment 25 will prevent any leaks.
When the overpressure in the feeding chamber 4 has been balanced to correspond to atmospheric pressure, the upper shutter 7 113~41 can again be opened. As far as Lhe expansible sealing tube 19 and the spare sealing element 25 of the upper shutter are concerned, the operation is the sarne as described in connection with lower shutter. Thus, before being opened, the shutter has been lowered on the lower support surface 16 of the guide 14 out of contact with the upper support surface as well as the sealing tube and the sealing element.
Thanks to the invention, the shutters can be opened and closed without beingin contact with their sealing means and the support surfaces in which said sealing means are mounted. In spite of this, a reliable sealing will be obtained due to a pressure difference across the shutter. The sealing means are located, well protected against damage and fouling, under the upper support sur-~ face of each guide, and the upper surface of each shutter can be made smooth and easy to clean. Due to the expansion of the sealing tube, the gap between the support surface and the shutter can amount to, e.g., ~5 to 5 mm, preferably 2 to 3 mm.
The drawings and the specifications related thereto are onlyintended to illustrate the idea of the invention. In its details, the arrangement according to the inventton may vary within the scope of the claims. Instead of using an expansible sealing tube, a non-expansible sealing element can be provided which is mounted on an expandalbe ring or some other expandable seat. The invention can also be carried out by means of a non-expansible sealing ele-ment which is mounted substantially immovably,on a support surface, the distance between the support surface 15, 16 being selected somewhat bigger so that the shutter also in this case is disengaged from the sealing element before movement of the shutter.
;
.
Claims (10)
1. A sealing arrangement for a shutter for a feeding chamber of a continuously operating pressure grinder, said feeding chamber being provided with a fixed guide for the shutter movable between an open and a closed position and with a sealing support surface provided with a sealing element facing the shutter for providing a sealing between the feeding chamber and the shutter in its closed position, the shutter being mounted with play on said guide so that the shutter is displaceable toward and away from said fixed support surface in a direction transverse to the path of movement of the shutter along said guide, and said sealing element being mounted on said fixed support surface so that, as the shutter is displaced in a direction away from said fixed support surface, the shutter is released from contact with said sealing element.
2. A sealing arrangement according to claim 1, wherein said sealing element is expandable by means of a pressure medium.
3. A sealing arrangement according to claim 1, wherein the shutter is plate-like and the guide comprises two support surfaces which between themselves form a slit movably receiving the shutter, one support surface of said guide forming said fixed sealing support surface, and the thickness of the edge part of the shutter movable in the slit being smaller than the distance between said support surfaces forming said slit so that the shutter is displaceable in said slit in a direction perpendicular to the plane of the plate-like shutter.
4. A sealing arrangment according to claim 2 wherein the feeding chamber is provided with a fixed support surface encircling the opening to be closed by the shutter, and the sealing element is mounted in a groove in said support surface.
5. A sealing arrangement according to claim 4, wherein said support surface is provided with a spare sealing element mounted in a second groove formed in said support surface and located adjacent said groove receiving said expansible sealing element.
6. A sealing arrangement according to claim 5, said sealing element is tubular, the inner space of said sealing element connected to a source of pressure medium and to the atmosphere respectively, via a control valve, and said control valve being arranged to connect the inner space of said sealing element in communication with said source of pressure medium when the shutter has been displaced to its closing position and with the atmosphere when the pressure in the feeding chamber has been brought to the same pressure level that prevails on the opposite side of the shutter.
7. A sealing arrangement according to claim 1, wherein the shutter is provided at the outlet side of said feeding chamber facing the grinding space.
8. A sealing arrangement according to claim 1, wherein the shutter is provided at the inlet side of said feeding chamber facing the atmosphere.
9. A sealing arrangement according to claim 1, wherein cleaning means are provided adjacent the path of movement of the sealing surfaces of the shutter for cleaning said surfaces.
10. A sealing arrangment according to claim 9, wherein said cleaning means comprises a brush, a scraper and/or water or air spray means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI792288A FI60251C (en) | 1979-07-20 | 1979-07-20 | TRAINING SYSTEM FOR TRAILERS AND TRAILERS |
| FI792288 | 1979-07-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1138241A true CA1138241A (en) | 1982-12-28 |
Family
ID=8512790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000353843A Expired CA1138241A (en) | 1979-07-20 | 1980-06-10 | Sealing arrangement for a shutter of a pressure grinder |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4305590A (en) |
| JP (1) | JPS5936039B2 (en) |
| CA (1) | CA1138241A (en) |
| DE (1) | DE3021197A1 (en) |
| FI (1) | FI60251C (en) |
| SE (1) | SE443588B (en) |
| SU (1) | SU1215627A3 (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3047033C1 (en) * | 1980-12-13 | 1982-11-25 | J.M. Voith Gmbh, 7920 Heidenheim | Wood grinder |
| JPS57171429A (en) * | 1981-04-13 | 1982-10-22 | Glatt Gmbh | Rotary disk type granulator |
| FI66440C (en) * | 1982-12-08 | 1984-10-10 | Tampella Oy Ab | RAMKONSTRUKTION FOER EN TRYCKSLIPMASKIN AV PRESSTYP |
| FI69653C (en) * | 1984-01-09 | 1986-03-10 | Tampella Oy Ab | FOERFARANDE OCH MATNINGSANORDNING FOER INMATNING AV EN VEDSATSI EN TRYCKSLIPMASKIN |
| FI101894B1 (en) * | 1996-12-16 | 1998-09-15 | Valmet Corp | Arrangements to provide continuous grinding in a wooden grind |
| US5957178A (en) * | 1997-11-20 | 1999-09-28 | Arasmith; Stanley Dale | Method and apparatus for processing pan-shaped wood members |
| US6125897A (en) * | 1997-12-22 | 2000-10-03 | Arasmith; Stanley Dale | Method and apparatus for processing pan-shaped wood members |
| CA2340552C (en) | 2000-03-14 | 2006-08-01 | Stanley Dale Arasmith | Improved method and apparatus for reducing oversized wood chips |
| US6510880B2 (en) | 2000-04-19 | 2003-01-28 | Stanley Dale Arasmith | Lumber trim end chipper |
| US7143796B2 (en) * | 2002-08-26 | 2006-12-05 | Arasmith Stanley D | Wood-reducing apparatus with continual feeder assembly |
| CN109569851B (en) * | 2018-12-20 | 2021-01-05 | 湖南正湘木业有限责任公司 | Compressed plate production system |
| CN109622173B (en) * | 2019-01-16 | 2020-01-10 | 中联重科股份有限公司 | Feeding cavity device and sand making machine |
| CN110450254A (en) * | 2019-09-10 | 2019-11-15 | 王艳 | A kind of mushroom wood pulverizer automatic feeding device |
| WO2022099443A1 (en) * | 2020-11-10 | 2022-05-19 | 菏泽市宁丰木业有限公司 | Method for using high-precision thermal grinder to implement production of high-quality fibre |
| CN112642569B (en) * | 2020-12-01 | 2022-11-25 | 镇江波菲尔生物科技有限公司 | Biomedical is with medicinal material grinding device that has anti falling function |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3690572A (en) * | 1969-12-06 | 1972-09-12 | Voith Gmbh J M | Two press grinder constructed for easy wheel replacement |
| US3596841A (en) * | 1970-06-02 | 1971-08-03 | Norton Co | Grinder for mechanical pulp making |
| US3690568A (en) * | 1970-06-11 | 1972-09-12 | Koehring Waterous Ltd | Wood grinding |
| US3693891A (en) * | 1971-06-24 | 1972-09-26 | Norton S Remmer | Wood grinding |
| FR2243619A5 (en) * | 1973-09-06 | 1975-04-04 | Joint Francais | |
| DE2606813A1 (en) * | 1976-02-20 | 1977-09-01 | Agfa Gevaert Ag | SEALING SYSTEM |
| FI57979C (en) * | 1978-02-16 | 1980-11-10 | Tampella Oy Ab | FOERFARANDE OCH SLIPVERK FOER SLIPNING AV VED UNDER TRYCK |
| FI57980C (en) * | 1978-02-16 | 1980-11-10 | Tampella Oy Ab | FOERFARANDE OCH SLIPVERK FOER AVLAEGSNING AV SLIPMASSA VID SLIPNING AV VED UNDER TRYCK |
| DE2812299A1 (en) * | 1978-03-21 | 1979-09-27 | Voith Gmbh J M | Wood pulp is produced from disintegrated tree trunks - by carrying out process at pressure and supplying water at above 100 degrees C |
| US4214760A (en) * | 1978-12-04 | 1980-07-29 | Godfrey Dwaine A | Seal for adjacent plates |
-
1979
- 1979-07-20 FI FI792288A patent/FI60251C/en not_active IP Right Cessation
-
1980
- 1980-06-03 US US06/156,133 patent/US4305590A/en not_active Expired - Lifetime
- 1980-06-04 DE DE19803021197 patent/DE3021197A1/en not_active Withdrawn
- 1980-06-10 CA CA000353843A patent/CA1138241A/en not_active Expired
- 1980-06-11 SE SE8004350A patent/SE443588B/en not_active IP Right Cessation
- 1980-06-24 JP JP55085809A patent/JPS5936039B2/en not_active Expired
- 1980-07-15 SU SU802947798A patent/SU1215627A3/en active
Also Published As
| Publication number | Publication date |
|---|---|
| SE8004350L (en) | 1981-01-21 |
| FI60251B (en) | 1981-08-31 |
| FI792288A7 (en) | 1981-01-21 |
| FI60251C (en) | 1981-12-10 |
| DE3021197A1 (en) | 1981-02-12 |
| JPS5936039B2 (en) | 1984-08-31 |
| US4305590A (en) | 1981-12-15 |
| JPS5617648A (en) | 1981-02-19 |
| SU1215627A3 (en) | 1986-02-28 |
| SE443588B (en) | 1986-03-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1138241A (en) | Sealing arrangement for a shutter of a pressure grinder | |
| BRPI1007221B1 (en) | SCRAPING SYSTEM FOR CLEANING A SURFACE ON A PAPER PRODUCTION MACHINE, SCRAPING SYSTEM FOR A PAPER PRODUCTION MACHINE, AND METHOD OF CLEANING A MOBILE SURFACE ON A PAPER PRODUCTION SYSTEM | |
| CA1148004A (en) | Method and apparatus for continuously processing wood | |
| CA1097118A (en) | Method of and a grinder for grinding wood under pressure | |
| US5077913A (en) | Self-cleaning steambox | |
| US4503770A (en) | Printing machine doctor blades | |
| US2643521A (en) | Sluice gate seal | |
| CA2937947A1 (en) | Startup burner assembly for recovery boiler and method | |
| SE8803281L (en) | SET AND DEVICE FOR GRINDING OF MATERIALS OF METALS AND METAL ALLOYS | |
| US7470122B2 (en) | Apparatus for removing melt from a melt residue stagnation zone in an injection molding apparatus | |
| US4094344A (en) | Apparatus for mending surface irregularities of wooden plates | |
| CN107649525B (en) | Prevent the spray header and Cold Rolling System of dropping liquid | |
| US4401277A (en) | Apparatus for producing mechanical wood pulp | |
| CA1096677A (en) | Method and apparatus for producing wood pulp in a wood-grinder | |
| US4405091A (en) | Apparatus for the production of mechanical wood pulp | |
| US4565077A (en) | Liquid treating apparatus | |
| EP1560899B1 (en) | An apparatus with a seal mechanism operable between a soild fuel feed system and a combustion chamber thereof | |
| US4381217A (en) | Method of increasing the temperature of shower water used in a wood grinding process | |
| US2702045A (en) | Steam water drain with a float controlled horizontal shutoff element | |
| EP0064771A3 (en) | Pressurised cooling pipe for the direct intensive cooling of rolling mill products | |
| EP0041812B1 (en) | Coke oven door frame cleaning apparatus | |
| GB1591811A (en) | Desludger type disc bowl centrifuges | |
| SU1154090A1 (en) | Apparatus for forced sprinking of polymeric material | |
| CN214466228U (en) | Swing valve with adjustable sealing structure | |
| GB1150816A (en) | Slide Valve For Use With A Cavity Such As A Concrete Mould |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |